None
Not Applicable
Not Applicable
The present invention relates to a catheter employed for diagnostic and/or therapeutic procedures in medicine, more specifically in minimally invasive cardiac electrophysiology studies and/or cardiac ablation procedures.
Catheters of the above described type are known in the art and, in particular, catheters capable of bi-directional curvature or lateral deflection upon movement of a remote manual actuator. A catheter of the aforesaid type employing tension/compression members without the need for a compression strut is known; and, in particular such a catheter is shown and described in my earlier U.S. Pat. No. 5,861,024 commonly owned by the assignee of the present invention. The catheter described in the aforesaid patent ""024 is of the type that is bi-directionally curveable in a generally planar curvature for entering the passages of the heart. In certain procedures the catheter is inserted through the femoral vein to a first chamber of the heart and it is then desired for the end of the catheter employing the electrodes to enter into another passage of the heart communicating with the first chamber of the insertion.
In addition, it has been desired to have the catheter conform to the inner periphery of certain passages in the heart and in particular the pulmonary vein for mapping or taking of electrical measurements of the condition of the inner periphery of the aforesaid passage or, in certain cases, performing ablation procedures on the passage of the heart.
Heretofore, it has been possible to deflect the catheter laterally with respect to the direction of elongation of the catheter casing; however, it has not been possible to provide such a catheter which could conform to the transverse peripheral configuration of the interior of the heart passage for which it is desired to conduct these studies and/or ablation procedures. Thus, it has been desired to find a way to map the inner periphery of the passage of the heart in a circumferential or transverse direction with a remotely inserted and remotely actuate deflectable tip catheter.
The present invention provides a solution to the above-described problem of utilizing a remotely insertable and deflectable tip catheter in a passage in a human heart and deflecting the distal end of the catheter in a substantially halo, loop, or lariat configuration of curvature in a plane generally perpendicular to the direction of elongation of the catheter. In other words, the distal end of the catheter is curved in a planar curvature about an axis, which is parallel to the direction of elongation of the catheter casing.
The catheter of the present invention employs tension/compression members anchored to the distal end of the catheter and which extend through the catheter casing to the proximal end and which are connected to an actuator for manually applying tension to one of the tension/compression members while compressing the other for remotely affecting the curvature of the distal end of the catheter when the catheter is inserted typically through the femoral vein into a passage in the heart.
The catheter of the present invention has a plurality of spaced electrodes disposed on the distal end of the casing of the catheter; and, each of these electrodes has an electrical lead connected thereto which extends through the casing to the proximal end of the catheter for external electrical connection thereto.
The catheter casing and tension/compression members have a permanent bend or preformed bend of about a right angle formed adjacent the proximal-most electrode; and, this pre-formed bend remains in the casing as the catheter is deflected and inserted through a guide tube placed in the vein for entry into the heart passage. Upon user movement of the remote actuator, which affects movement of the tension/compression members inside the casing, the distal end of the catheter deflects laterally or curls into a xe2x80x9chaloxe2x80x9d configuration in a plane generally at right angles to the direction of elongation of the catheter, or in other words, in a plane parallel to the axis of curvature of the pre-formed bend, which axis is at right angles to the direction of elongation of the catheter casing. The halo is capable of extending in curvature through an angle of at least 270xc2x0 and thus disposes the electrodes transversely or circumferentially at a single station about the major portion of inner periphery of the passage in the heart. This disposition of the electrodes enables an electrical mapping of the inner periphery of the heart passage or the performance of ablation procedures at spaced intervals about the circumference of the interior of the heart passage. Upon reversal of the remote manual actuator attached to the proximal end of the catheter casing, the halo is uncurled to a straight configuration. The catheter may then be removed from the heart passage through the guide tube in vein, usually the femoral vein, from which it was inserted. In the preferred embodiment of the invention the initial permanent or pre-formed bend in the casing is formed at about 90xc2x0 in catheters having the minimum radius for the curled loop and about 450xc2x0 for catheters having a larger curled loop.
The catheter of the present invention has the permanent or pre-formed bend therein about an axis perpendicular to the direction of elongation of the catheters; and, the portion of the catheter distal the pre-formed bend is preferably manually flexed and inserted into the vein for entry into the heart passage. The pre-formed bend remains formed in the catheter. Upon user movement of the remote actuator, flexure of the catheter is facilitated in a plane normal to the direction of elongation of the catheter casing to thereby form a xe2x80x9chaloxe2x80x9d for facilitating circular electrical mapping of the interior of the heart passage into which the halo is situated.